>>Can somebody explain to me why those who run eyeball networks are able >> to block outbound packets when the customer hasn't paid their bill, >> but can't seem to block packets that shouldn't be coming from that >> cablemodem? > >i suspect the non-payment case is solved at a layer below three
In a DOCSIS network the source address verification (as Tony said) is typically done on the CMTS IIRC. Turning a customer off for non-payment is done in an accounts management / billing system. While I am sure continuing to agree with each other that spoofing is bad, we lack actionable data. ;-) As I said in another thread, I think someone / some group needs to invest to collect actual data and share the results openly. So any volunteers out there? I¹m sure there are lots of ways to underwrite independent research on the subject (contact me off-list). Jason